Angus Macnab

Hall magnetohydrodynamics simulations of end-shorting induced rotation in field-reversed configurations

End-shorting of the open field lines that surround a field-reversed configuration (FRC) is believed to contribute to its observed rotation. In this study, nonlinear extended magnetohydrodynamics (MHD) simulations were performed that detail the end-shorting process and the resulting spin-up of the FRC. The tangential component of the electric field ET is set to zero at the axial boundaries in an extended MHD model that includes the Hall and ∇Pe terms. This shorting of the electric field leads to the generation of toroidal fields on the open field lines, which apply a torque leading to a rotation of the ions on the open field lines. The FRC then gains angular momentum through a viscous transfer from the open field line region. In addition, it is shown that spin-up is still induced when insulating boundaries are assumed.End-shorting of the open field lines that surround a field-reversed configuration (FRC) is believed to contribute to its observed rotation. In this study, nonlinear extended magnetohydrodynamics (MHD) simulations were performed that detail the end-shorting process and the resulting spin-up of the FRC. The tangential component of the electric field ET is set to zero at the axial boundaries in an extended MHD model that includes the Hall and ∇Pe terms. This shorting of the electric field leads to the generation of toroidal fields on the open field lines, which apply a torque leading to a rotation of the ions on the open field lines. The FRC then gains angular momentum through a viscous transfer from the open field line region. In addition, it is shown that spin-up is still induced when insulating boundaries are assumed.

Simulations of the Supersonic Translation, Collision, and Merging of Two Field-Reversed Configurations for Plasma Heating

Axisymmetric extended magnetohydrodynamic (MHD) simulations, which detail the supersonic translation, collision, and merging of two field-reversed configurations, were performed. Five theta pinch coils placed along the radial walls of the chamber accelerate the compact toroids toward each other and compress the resulting doublet configuration until it forms a single compact toroid. Two-fluid effects are observed to significantly speed up the merging process as compared against resistive MHD calculations.